mysql java自增序列号

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50) NOT NULL,
    email VARCHAR(100) NOT NULL
);

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class UserDAO {
    private static final String DB_URL = "jdbc:mysql://localhost:3306/mydatabase";
    private static final String USER = "username";
    private static final String PASS = "password";

    public void addUser(String username, String email) {
        String sql = "INSERT INTO users (username, email) VALUES (?, ?)";

        try (Connection conn = DriverManager.getConnection(DB_URL, USER, PASS);
             PreparedStatement pstmt = conn.prepareStatement(sql)) {

            pstmt.setString(1, username);
            pstmt.setString(2, email);
            pstmt.executeUpdate();

        } catch (SQLException e) {
            System.out.println(e.getMessage());
        }
    }

    public static void main(String[] args) {
        UserDAO userDAO = new UserDAO();
        userDAO.addUser("john_doe", "john@example.com");
    }
}

ALTER TABLE users MODIFY COLUMN id BIGINT AUTO_INCREMENT;